Intermittent arming device for a mine



Jan. 2, 1962 H. w. SEMON 3,015,272

INTERMITTENT ARMING DEVICE FOR A MINE Filed Nov. 3, 1949 FIG. 1.

H.W. SEMON United States Patent 3,015,272 INTERMITTENT ARMING DEVICE FORA MINE Howard W. Semon, Philadelphia, Pa. (1130 Maryland Ave. NE.,Washington 2, D.C.) Filed Nov. 3, 1949, Ser. No. 125,362 6 Claims. (Cl.10216) (Granted under Title 35, US. Code (1952) see. 266) This inventionrelates to an intermittent arming device for a mine which controls theperiod of time during which the mine is armed and disarmed respectively,thereby to provide intermittent arming of the mine. Such a device isadvantageous in that it increases the labor and difiiculties encounteredby the enemy in sweeping a mine infested area since only a fractionalnumber of the mines would be actuated or swept by a single sweepingoperation.

The military value of mine warfare, as is well known, is increased bylengthening the useful life of a mine and by decreasing thesusceptibility of a mine to sweeping. In prior devices employingintermittent arming of a mine it has been the general practice tocontrol the armed and unarmed periods of the mine from a short station.Such devices have not been altogether satisfactory under all conditionsof warfare for the reason that a control connection must be establishedbetween the mine and the control apparatus on the shore.

The present invention accomplishes both of the foregoing desirablefeatures by means of time measuring devices which require no outsidecontrol or regulation after the initial setting and possesses none ofthe foregoing disadvantages of the prior devices.

One of the objects of this invention is to provide a system whichinherently arms and disarms a mine repeatedly in accordance withpredetermined time limits.

Another object of this invention is the provision of separate means forgoverning the length of the armed period and the length of the disarmedperiod respectively of a mine.

Another object of this invention is the provision of a device whichincreases the difficulties of making a complete sweep of a mined area.

Another object of this invention is the provision of a device whichlengthens the useful armed life of a mine by making interrupted powerdemands on the mine battery thereby allowing regeneration of thebattery.

Still other objects and advantages of the invention not specifically setforth hereinabove are those implied or inherent in the construction,combination and arrangement of parts, as will become more clearlyapparent from the following description, reference being had to theaccompanying drawings in which:

'FIG. 1 is a diagrammatic view of the circuit and mechanism of thepresent invention according to a preferred embodiment thereof; and

FIG. 2 is a sectional view of a specific one'of the timing devicessuitable for use with the present invention, the other timing devicebeing identical therewith.

Referring now to the drawings for a more complete understanding of theinvention, FIG. 1 thereof discloses a preferred embodiment and comprisesfour units: (1) the battery power source 3, (2) the firing mechanism 4,(3) the arming clock 5, and (4) the arming and disarming control devices8 and 9.

. The arming and disarming control devices 8 and 9 are caused to operateupon the closing of contact A of the hydrostatically controlled armingclock 5 which may be of any type suitable for the purpose such, forexample, as the arming clock disclosed in the patent to Van Atta et al.,for Control System and Device Therefor for Submarine Mines, No.2,399,523, issued on April 30, 1946.

The arming clock 5 has a pair of cam controlled contacts A and E adaptedto be closed in the order named in predetermined time delayed relationin response to the operation of the hydrostat 6 after the mine isplanted.

The mine is placed in target-responsive or tar-get nonresponsivecondition by the operation of switch B of the armed interval controldevice 8. As shown in FIG. 1 switch B is included in the circuit of thefiring mechanism 4, said firing mechanism being of any type suitable forthe purpose such, for example, as the firing mechanism disclosed in thepatent to Van Atta et a1. referred to hereinbefore.

The first timing device 8 comprises a shaft 10 on which is mounted aclock type power spring 11 shown in FIG. 2, which has its inner endattached to the shaft 10 and its outer end attached to the frame 26 ofthe armed condition establishing device 8. A large gear 12 is connectedto the lower end of the shaft 10 and is intermittently driven clockwiseby a pinion 14 which is powered by an electric motor 15. A mechanicalself-starting escapement 16 of any type suitable for the purpose such,for example, as the escapement disclosed in the patent to Van Atta eta1. referred to hereinbefore, is connected to the large gear 12 througha ratchet-type clutch 17 so arranged that the escapement 16 is drivenonly when the shaft 10 is rotated counter-clockwise by the power spring11. The escapement 16 controls the rate of rundown of the armed intervalcontrol device 8. At the top of shaft 10 is mounted a switch disk 13which is held secured thereon in any suitable manner as by nut 23-.Integral with the switch disk 13 is a protuberance 18, FIG. 1, arrangedto operate switches B and C as the disk rotates. One blade of switch Chas a rider 24 attached thereto which is inherently spring-biased towardand slideably contacts the side periphery of the switch disk 13 and theprotuberance 18 thereof. The outer blade of switch B is rigidly attachedto the switch disk riding blade of switch C by means of insulated rod25. This arrangement causes switch C to be closed and switch B to besprung open by rod 25 when the protuberance 18 forces rider 24 outwardlyagainst its inherent inward spring pressure and the inherent inwardspring pressure of the B spring blade to which rod 25 is attached.

Immediately below the switch disk 13 is a switch arm 19, as viewed onFIG. 2, pivotally mounted on hearing 33 which is fixedly attached to theupper plate 27 of the clock frame 28. A pin 20 is provided at one end ofswitch arm 19 which projects into the timing slot 21 of switch disk 13.At the other end of switch arm 19 are provided two switch blade engagingsurfaces 30 and 31 which contact and actuate the inner inwardlyspringbiased electrical contact blade of switch D which is included inthe armed device winding motor circuit. The contact arm 19 is arrangedto provide a toggle action so that either switch closing surface 30 orswitch opening surface 31 is in contact continuously with theaforementioned inner blade of switch D.

The switch disk timing slot 21 is provided with an adjustable timingslot stop 22 which may be used, in the case of device 8, to set thedesired period for which a mine is to be armed. As seen in the drawingin FIG. 1 the switch disk 13 is provided with a plurality of timeindicia which are arranged along the timing slot 21. By adjustment ofthe stop 22 the clockwise windup by motor 15 is regulated since the stop22 will snap the toggle action contact arm 19 clockwise, as viewed inthe drawing, when the switch disk 13 has rotated sufficiently, therebyallowing the inner blade of switch D to spring inwardly into contactwith surface 31 thereby to cut off the power at switch D to motor 15.

The unarmed interval control device 9 comprises mechanism similar to thearmed interval control device 8 with the exception that switches B and Care replaced by switch F operated by protuberance 18'. The componentparts of the unarmed interval control device 9 have the same numerals assimilar parts of the armed interval control device 8 and operate in asimilar manner but are primed for the purpose of description.

The battery power source 3 is provided to supply the two electricwinding motors 15 and 15' with the electrical power needed for eachmotor to wind the power spring 11 and 11 individual thereto.

The operation of the intermittent arming device for a mine will now bedescribed in detail for a more complete understanding of the invention.Essentially the arming and disarming process involves alternatelymeasuring armed and unarmed time intervals; the measurement of each ofthe intervals being initiated at the termination of the other interval.The armed time interval device 8 is used to maintain the armed conditionof the mine and the unarmed time interval device 9 is used to maintainthe unarmed condition of the mine.

With the armed interval control device 8 in fully run down condition, asshown in FIG. 1, the switch disk 13 is in the position shown with thezero time end of slot 21 in engagement with pin 20 thereby holdingswitch arm 19 counter-clockwise so that switch blade engaging surface 30springs switch D to closed position. The protuberance 18 is engagingrider 24 thereby causing switch C to be closed and switch B to beopened.

When the mine is laid, arming clock is started and after a predeterminedsafety period the arming clock 5 causes switch A to be closed whichcompletes the armed interval control device motor circuit and allowscurrent to flow from battery 3, through the closed switch F, throughswitch D to the electric motor 15, and thence through switch A back tothe battery. The pinion 14 and large gear 12 cause the shaft to rotateclockwise, thereby winding the power spring 11. The escapement 16, itwill be recalled, is unaffected by clockwise rotation of shaft 10 sincethe natchet clutch 17 is so arranged that only counter-clockwiserotation of shaft 10, as powered by the power spring 11, aotuates theescapement.

As the switch disk 13 rotates clockwise, switch C is caused to open andswitch B is caused to close, thereby placing the firing mechanism 4 inarmed condition so that the mine is in readiness to explode uponactivation by an enemy vessel. The actual time between the closing ofswitch A and the opening of switch C may, for example, be about 30seconds.

Since the interval between the closing of switch A and the closing ofswitch E of the arming clock 5 need only be long enough to allow thearmed switch disk 13 to rotate sufiiciently to open switch C, the armingclock may be set to close switch E at a predetermined time period afterswitch A is closed, for example 60 seconds. Switch E when closed placesthe unarmed interval control device motor circuit in readiness toreceive current when the armed interval control device 8 runs down andcloses switch C.

When the adjustable time slot stop 22, which has been set to the desiredarmed interval, contacts and pivots the switch arm 19 clockwise, theswitch blade engaging surface 31 causes the switch D to open by itsinherent spring tension, thereby opening the associated motor circuitand allowing the power spring 11 to rotate the shaft 10 of the armedinterval control device 8 counter-clockwise. The counter-clockwiserotation rate of shaft 10 is controlled by the escapement 16 to about 45degrees of rotation per hour. As stated hereinbefore the ratchet clutch17 allows actuation of the escapement only when the shaft 10 is rotatedcounter-clockwise.

The mine, therefore, becomes armed when switch B is closed and becomesdisarmed when the switch disk 13 has rotated counter-clockwisesufficiently to close switch C and open switch B.

When switch C is closed current passes from the battery 3 to the unarmedinterval control device motor 15', through the closed switch D of thecontrol device 9, through switch C, through switch E and back to thebattery 3. The unarmed device motor 15 causes clockwise rotation of theswitch disk 13' in the unarmed device 9, which switch disk opens switchF.

After switch F is opened, the zero end of the slot 21 in the armeddevice switch disk 13 is rotated into engagement with the pin 20 ofswitch arm 19 and snaps the switch arm 19 counter-clockwise therebyclosing switch D of the device 8. The armed device motor circuit isthereby placed in readiness to receive current when the switch F isclosed by the unarmed device switch disk 18'. The remainder of theoperation of the unarmed device 9, it will be understood, is similar tothe armed device 8 operation as described above.

When the unarmed device 9 approaches a rundown condition theprotuberance 18' closes switch F which causes the armed device motor 15to rotate its switch disk 13 clockwise which opens switch C, and closesthe mine arming circuit switch B. After switch C is opened the zero endof the slot 21 in the unarmed device switch disk 13' is rotated intoengagement with the pin 20 of switch arm 19 and snaps the switch arm 19counter-clockwise thereby closing switch D' of the device 9. The unarmeddevice motor circuit is thereby placed in readiness to receive currentwhen the switch C is closed again.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

The terms and expressions used in this specification in reference to myinvention are employed as terms of description and not of limitation.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A part-time mine arming circuit for a mine comprising, incombination, means for placing the firing mechanism in target responsivecondition for a first predetermined period of time, and interruptingmeans operatively connected to said first-named means for cyclicallyplacing the firing mechanism in a target non-responsive condition for asecond predetermined period of time, said means for placing the firingmechanism in a target responsive condition including an armed intervalcontrol device having an electric motor, a shaft geared to said motor, apower spring which is wound up by said shaft, a switch disk having aslot therein mounted on said shaft, a protuberance integral with saidswitch disk, electrical switch means operated by said protuberance forarming circuit energization, a fixed bearing around said shaft, a togglearm pivotally mounted on said bearing having a pin at one end disposedwithin the slot in the switch disk and having opening and closing switchengaging surfaces at the other end, switch means for the electric motorlocated at said other end for operation by said engaging surfaces, aself-starting escapement, and ratchet clutch power transmission meansfor connecting said escapement to said shaft to allow activation of theescapement only when the shaft is rotated by the power spring.

2. In a part-time arming device for a mine firing mechanism, an armedinterval control device which causes the mine to be target responsivefor a predetermined period, and an unarmed interval control device whichcauses the mine to be target non-responsive for a predetermined period,each of said control devices comprising similar timing means adapted tocyclically cause the target responsive and target non-responsiveconditions of the mine to be repetitive, wherein one of said similartiming means comprises: means for rapidly supplying power, powerreceiving and storing means, adjustable means for regulating the amountof power supplied to the receiving and storing means, retarding meansfor governing the rate of dissipation of the power from the powerreceiving and storing means, and electrical switch and circuit means forplacing the other timing means in readiness for operation.

3. In a part-time arming device for a mine firing mechanism, a powersource, a firing mechanism, unarmed interval control means connected tothe power source and adapted to maintain the firing mechanism in targetnonresponsive condition for a predetermined period; armed intervalcontrol means comprising: first power storing means, first means fortransferring power from the power source to the first power storingmeans, first retarding means for dissipating the power in the firststoring means at a controlled rate, and first means actuated by thefirst power transfer means just after the start of operation of thefirst power storing means for placing the firing mechanism in targetresponsive condition and for preventing the supply of power to theunarmed interval control means and also just before complete powerdissipation for placing the firing mechanism in target non-responsivecondition and for allowing the supply of power from the power source tothe unarmed interval control means; said unarmed interval control meanscomprising: second power storing means, second means for transferringpower from the power source to the second power storing means, secondretarding means for dissipating the power in the second storing means ata controlled rate, and second means actuated by the second powertransfer means just after the start of operation of the second powerstoring means for preventing the supply of power to said armed intervalcontrol means and also just before complete power dissipation forallowing the supply of power from the .power source to the armedinterval control means; primary control means for stopping the supply ofpower to the first power storing means after a predetermined amount ofpower has been supplied and upon complete power dissipation by the firstretarding means preparing the armed interval control means for receiptof further power through the unarmed interval control means; andsecondary control means for stopping the supply of power to the secondpower storing means after a predetermined amount of power has beensupplied and upon complete power dissipation by the second retardingmeans preparing the unarmed interval control means for receipt offurther power through the armed interval control means.

4. An intermittent arming device for a mine firing mechanism comprising,in combination, a source of power, first and second means forindividually storing and releasing predetermined amounts of energy,means individual to said energy storing and releasing means forreleasing said energy therefrom in predetermined periods of time, firstand second electroresponsive means individual to said energy storagemeans for transferring said energy thereto from said source of powerwhen the electroresponsive means are selectively connected thereto,means operated by said first energy storing and releasing means forrespectively disconnecting and connecting said second electroresponsivemeans from and to the source of power as storing of energy in said firstenergy storing and releasing means is initiated and as release of energytherefrom is terminated respectively, means operated by said secondenergy storing and releasing means for respectively disconnecting andconnecting said first electroresponsive means from and to said source ofenergy as storing of energy in said second energy storing and releasingmeans is initiated and as release of energy therefrom is terminatedrespectively, and means operated by said first energy storing andreleasing means during said storing and release of the energy thereoffor arming the mine firing mechanism.

5. An intermittent arming device for a mine comprising, in combination,a pair of means for successively storing and releasing energy, meansindividual to said pair of means and controlled by each other forcausing energy to be stored in each when release of energy from theother is terminated, means individual to said pair of means for causingrelease of said energy therefrom at predetermined rates, and meanscontrolled by one of said pair of means for arming the mine during thestoring and release of the energy thereof whereby the mine is armed andunarmed alternately for predetermined intervals of time.

6. An intermittent arming device for a mine firing mechanism comprising,in combination, a pair of means for successively storing and releasingenergy, means controlled by one of said energy storing and releasingmeans for initiating storing of energy in the other as release of energyfrom the one is terminated, means controlled by said other of the energystoring and releasing means for initiating storing of energy in said oneof the energy storing and releasing means as release of energy from theother is terminated, means controlled by said one of the energy storingand releasing means for arming said firing mechanism during the energystoring and releasing interval thereof, and means individual to saidpair of energy storing and releasing means for causing the energy to bereleased therefrom at predetermined rates whereby the mechanism is armedand disarmed alternatively for predetermined intervals of time.

References Cited in the file of this patent UNITED STATES PATENTS2,060,198 Hammond Nov. 10, 1936

